Low-recoil, variable-range missile projector



June 6,1961 A. L. WAXMAN 2,986,973

LOW-RECOIL, VARIABLE-RANGE MISSILE PROJECTOR Filed Sept. 20, 1954 UnitedStates Patent Y 2,986,973. Low-RECOIL, VARIALE-RANGE Mesnil?. PRoJEc'roRThe invention described herein may be manufactured and used by or forthe Government of the United States ef rAmerica for governmentalpurposes without the payment of any royalties thereon or therefor.

The present invention relates toa low-recoil, variablerange missileprojector and more particularly to a lowrecoil, variable-range missileprojector for antisubmarine warfare which is provided with exhaust gasventing structure to selectively vary the range ei. the missile Whilemaintaining Optimum.. Water entry and underwater trajectery- Presentmissile projectors for combating Submarines are generally fixedlaunchers with respect to train and elevation and variations in rangecan be obtainedv in a mortarlike method only by changing the amount of'launching explosive to be red. This system is inadequate in that thelaunching explosives have to be prepac'ked to fuliill different rangerequirements, yand as each `range requires a certain amount ofexplosive, the number of total ranges possible are severely restricted.The limited ranges aforded by this type of projector necessitate thehazardous operation of maneuvering the attack vessel within the range ofthe projector in order that the missile can be successfully explodedwithin an effective proximity to the underwater target.

The prior art antisubmarine missile projectors have the additionaldisadvantage of ybeing restricted to a relatively small weight missilebecause their stationary structures cannot effectively counteract'largerecoil forces.

The present invention is vbelieved to overcome the above-mentioneddeficiencies now present in missile projectors for antisubmarine warfareby the provision of a projector which has a low recoil and a variablerange made possible by novel structure which allows controlled ventingof exhaust gases of the propellent explosive.

An object of the present invention is the provision of a projector forantisubmarine ordnance having controllable means for the escape ofpropellent gas forces from the expansion chamber to the atmosphere tovary the missile range.

Another object is to provide a low-recoil missile projector whichenables a missile to have a xed angle of water entry and underwatertrajectory at various ranges.

A further object of the invention is the provision of means for varyingthe range of a projected missile without a change in the weight oramount of explosive propellant and without changing the elevation of thebarrel of the projector with respect to the horizontal.

A further object is the provision of a relatively lightweight projectorin comparison with the weight of the projectile launched.

A still further object of the present invention is the provision of aprojector for launching mortar-type ammunition having a remotelycontrolled range varying system.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

FIG. 1 is a longitudinal sectional view partly in elevation of apreferred embodiment of the invention;

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FIG. 2 is a similar view of a modied form of the mis.- sile projector;and

FIG. 3 is a perspective view, partially broken away, of the valve andassociated linkage.

The present invention is a depth charge projector which has a smoothbore barrel attached to a pressure vessel, such as an expansion chamber,having circumferentially spaced openings or vents through the wallthereof to vent to the atmosphere propellent gas from the pressurevessel. The projectile range may be controlled by varying these ventopenings. Escape ports through the after section .of the breech serve tocounteract much of the recoil of the projector by permitting the escapeof propellent gas forces rearwardly to the atmosphere.

Referring now to the drawings, wherein like reference charactersdesignate like or corresponding parts through,- out the several views,FIG. 1 illustrates a preferred ernbodiment wherein a missile projector10 has a barrel 1 1 with muzzle end 12 and a chamber end 13. The barrel11 is attached at its chamber end `13 to an expansion chamber 14 havingcircumferentially spaced vents 15 through the wall 16 thereof leading tothe atmosphere. Concentrically spaced from the inner surface 17 ofexpansion chamber 14 and engaged to the inner surface of a breech plug18 is a powder case receiver A19 having lperforations in the cylindricalwall 20 thereof and being open at the forward end Z1 of the receiverjust aft of the barrel 1v1. The cylindrical wall 20 of the powder casereceiver 19 extends longitudinally forward of the vents 15 to act as abale to direct propellent gas forces toward the barrel 11 and behind aprojectile 22 in barrel 11. As the initial thrust force of the explosionof a powder charge pushes the projectile 22 through the barrel 11, thepropellent gas is directed rearwardly around the exterior of wall 2.0 ofpowder case receiver 19 in the space between the outer surface of thepowder case receiver 19 and the inner surface 17 of the expansionchamber wall 16 and through the breech plug 18 via expansion chamberventuri ports 23 axially bored therethrough.

A 'variation in range of the projectile 22j is obtained by controllingthe opening size of vents 15 by a valve such asa sleeve 24 mounted onthe outside of wall 16. The sleeve 24 moves longitudinally on said wall16 over the vents 1S to open or close them fully or partially by meansof an actuating mechanism such as worm gear 25 engaging exterior threads26 on sleeve 24 to rotate the sleeve on interior threads 27 which aremeshed with a threaded portion 28 of the expansion chamber wall 16. Theworm gear 25 is suitably connected by linkage 29 to a range controlmaster 30 at a removed position from the projector 10. The sleeve 214 isprovided with a forwardly open integral bell flange 31 to direct theexpelled gases forwardly thus to some extent compensate for the tendencytoward overcompensation for the recoil energy at shorter target ranges.

The impulse ammunition used as an explosive propellent force may be ofthe type commonly used in launching depth charges fro-m mortar or bombtype projectors. The propelling charge is normally contained in acartridge case having a forward disk and end wad and, on tiring thepropelling charge, the disk retains the gas of the initial explosion topromote a build-up of pressure in order that a proper pressure fore'icient combustion is established and that, when released, the pressurewill overcome the inertia of the projectile to start its expulsion.

The projectile best adapted for ammunition for the present invention isthe bomb type, vane stabilized depth charge having the front end, orogive, of a blunt curvature. The blunt nose of the projectile is chosenbecause tory characteristics desired.

A faired nose projectile has the inherent fault of resurfacing due tothe forces of the water against the nose curved surface.Y The projectile22 may have a gas seal ring such as ring 32 in Vclose tolerance with thebarrel bore to prevent the propellentv gases from going'forward aroundthe projectile rather than pushing behind the projectile. Y Y

A modification of the projector of FIG. l is the projector illustratedin FIG. 2 which has a barrel 41, an expansion chamber 42 connected tothe after end of barrel 41, and a breech plug 43 closing the end of theexpansion chamber 42 and having a venturi port 44 axially boredtherethrough. A laterally extending side member 45 is attached to theexpansion chamber 42 to receive a powder charge in the outermost portionthereof. The cylindrical wall 46 of the side member 45 has radiallyspaced vents 47 located adjacent to and equidistant from the expansionchamber and the side member juncture 50. A hatch 48 is provided in theend of side member 45 to receive the propellent charge 49. A three-wayvalve 51, as shown by FIG. 3, rotatably secured within the side member45 in a plane perpendicular to the longitudinal axis of the side memberso as to cooperate with the vents 47 to vary the openings thereof to theatmosphere. The centrally located passage 52 of three-way valve 51connects the side member with expansion chamber 42. Valve 51 is rotatedby either a manually or electrically operated lever arm 53 which extendsfrom the exterior of the side member through slot 54 to a rigidconnection 55 with rotatable valve 51. Range selection is procured inthe projector modication of FIG. 2 by adjusting the vent opening byvalve 51 to allow a quantity of propellent gas to escape therethrough.The main force of the propellent gas continues through the passage 52 toexpansion chamber 42 and thence to the barrel 41 to expel the projectile56. Recoil of the projector 57 is counteracted by the provision otventuri port 44 which allows the rearward escape of propellent gas.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

l. A low-recoil, variable-range missile projector cornprising a barrel,an expansion chamber having a Venturi port axially extending through therear thereof and connected to said barrel, a powder case receivingmember laterally attached to said expansion chamber by a valvecontaining means intermediate said expansion chamber and said powdercase receiving member, said valve containing means having radiallyspaced vents located through the wall thereof, a valve rotatably mountedwithin said valve containing means having an opening axiallytherethrough to allow passage of gases from said powder case receivingmember to said expansion chamber and further having a plurality of portspositioned to be in alignment with said radially spaced vents when thevalve is in a predetermined position, and means to adjust said valvewhereby the alignment of the missile projector is unaiected by variableventing of burning gases to the atmosphere. v

2. A low-recoil, variable-range missile projector as in claim 1 whereinsaid means'to yactuate the valve comprises a lever arm connected to saidvalve and extending outwardly through Ia slotted opening in the wall ofsaid powder case receiving member.

3. A low-recoil, variable-range ymissile projector comprising, a barrel,an expansion chamber connected to said barrel and having a venturi portaxially extending through the rear thereof, a powder charge receivingmember later# ally attached to said expansion chamber by a casing means,said casing means having radial vents, an annular valve rotatablymounted Within said casing means and having openings extending radiallytherethrough, said openings being so arranged as to fall in alignmentwith said vents when the valveris rotated into a predetermined position,said valve having an actuating member attached thereto and extendingthrough a slotted opening inthe wall of said powder charge receivingmember for rotating said valve to produce variable venting of burninggases to the atmosphere.

References Cited in the le of this patent UNITED STATES PATENTS1,299,136 Davidson Apr. 1, 1919 1,322,980 Wale Nov. 25, 1919 1,559,183Rimailho Oct. 27, 1925 2,093,058 Savani Sept. 14, 1937 2,094,305 SavaniSept. 28, 1937 2,378,735 Shaffer June 19, 1945 2,417,983 Holman et alMar. 25, 1947 2,444,949 Musser July 13, 1948 FOREIGN PATENTS 404,186Great Britain Jan. 11, 1934

